?? and ?. and ?.() operators in javascript

Asked May 20 '21 at 21:38

Active May 20 '21 at 21:50

Viewed 29 times

-2

While I was reading about Javascript I found that there are ?? and ?. and ?.() operators . I understood what ?. means but couldn't understand ?? and ?.() {This operator is called conditional invocation} . I searched google about ?? and ?.() but couldn't get that much help .

I found these operator while reading "Javascript the definitive guide 7th edition" by david flanagan .

function1?.();
// when I try to use a function which I didn't define then I get a error so then What is the need of this operator

// but if I try this ...

function square(x, log) { 
log?.(x);             
return x * x; 
}

// this works fine

Please help ..

edited May 20 '21 at 21:50

asked May 20 '21 at 21:38

Hasnath abdullah aknd

did you search for "javascript double question mark"? this is the first result in google https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_operator – Andy Ray May 20 '21 at 21:40
1

[nullish coalescing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_operator), [optional chaining](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining) – ASDFGerte May 20 '21 at 21:41
so then what is ?.() – Hasnath abdullah aknd May 20 '21 at 21:46
That's covered in both the duplicate and ASDFGerte's second link. – John Montgomery May 20 '21 at 21:48
`const function1 = undefined; function1?.();` works just fine for me, what error are you getting? – John Montgomery May 20 '21 at 21:53
I am trying do is : – Hasnath abdullah aknd May 20 '21 at 21:56
if I defined a function1 then let this function run or just stop . – Hasnath abdullah aknd May 20 '21 at 21:56

?? and ?. and ?.() operators in javascript

0 Answers0